A real-world data study of more than 11.17 million people from Chile showed that after receiving two doses of the Coxing vaccine, either homologous or heterologous booster vaccination, it provided a high level of protection against severe illness and death.
The study also suggests that 3 doses should be considered as the base immunization regimen for inactivated vaccines.
On April 23, a Chilean team published a large-scale study of real-world data at Lancet Global Health comparing the effectiveness of homologous and heterologous enhancements based on 2 doses of Koxing vaccine.
Specifically, on the basis of 2 doses of CoronaVac, the third dose of Coshing vaccine is given, or the Pfizer-BioNTech vaccine (BNT162b2) and The Oxford-AstraZeneca vaccine (AZD1222) are administered sequentially.
New data on inactivated vaccines to prevent severe illness and death
There is growing evidence that the humoral immune response decreases over time after any COVID-19 vaccine, which may also reduce vaccine protection against infections and diseases. New variants of the coronavirus, such as Delta and Omexjong, have all seen immune escape.
As China's inactivated vaccine, which has a global supply of more than 1/3, how effective its real-world protection is has become a topic of public concern.
The Chilean study included 11174257 individuals over the age of 16. Among them, 4127546 people were vaccinated with 2 doses of Koxing vaccine, on this basis, 1921340 people (46.5%) were vaccinated with AZD1222 in the 3rd dose, 2019260 people (48.9%) and the 3rd dose was vaccinated with BNT162b2, 186946 people (4.5%) the 3rd dose of cognate vaccination was given to the Koxing vaccine.
This is also the largest sample size of the Coxing vaccine in the real world.
It should be noted that because the study was conducted before the November 2021 Opichron outbreak, the findings do not address the effectiveness of the vaccine on Themikron.
The results showed that in terms of effectiveness in preventing symptomatic infection, the effectiveness rate of homologous vaccination of 3 doses of Covesy vaccine was 78.8%, 96.5% of 2 doses of Coxing + BNT162b2, and 93.2% of 2 doses of Coxing + AZD1222.
In terms of effectiveness in preventing hospitalization, 86.3% of the 3 doses of Cosh vaccine homology, 96.1% of 2 doses of Cosh + BNT162b2, and 97.7% of 2 doses of Cosh + AZD1222.
In terms of effectiveness in preventing the entry into the ICU, 92.2% of the 3 doses of Cosh vaccine homologous vaccination, 96.2% of 2 doses of Coxing + BNT162b2, and 98.9% of 2 doses of Coxing + AZD1222.
In terms of effectiveness in preventing death, 86.7% of 3 doses of Cosh vaccine homologous vaccination, 96.8% of 2 doses of Coxing + BNT162b2, and 98.1% of 2 doses of Coxing + AZD1222.
The results of this study showed that 3 doses of the vaccine had a good effect on preventing the pre-Omiljunn strain of COVID-19 in terms of infection, severe illness, critical illness and death.
That is, individuals who have been fully vaccinated with two doses of sub-Koxing vaccine, whether homologous or heterologous booster vaccination, can provide a high level of COVID-19 protection, including prevention of severe illness and death.
At the same time, heterologous booster vaccination has shown higher vaccine efficacy than homologous booster vaccination and has also supported sequential vaccination.
3 doses are recommended as the base immunization
However, the study was done before the emergence of the Omikejong variant and did not involve effectiveness against Omikeron. Previous research from the University of Hong Kong has further supplemented real-world data on coping with the Opmi kerong variant.
On March 22, the University of Hong Kong's Li Ka Shing School of Medicine released a study entitled "Forward-looking Planning for the Fifth Wave of the Epidemic in Hong Kong", in which a set of vaccine effectiveness data from Hong Kong showed that for the elderly over 60 years old, the three doses of The Cotegrid vaccine and the BNT162b2 vaccine were more than 90% effective in preventing severe illness and death.
The results showed that after completing three doses of intensive vaccination for people over 60 years old, the effectiveness rate of The Anti-Severe Disease of the Coxing Vaccine was 97.9%, and the effectiveness rate of BNT162b2 against severe illness was 98%,00% for the prevention of death; the effectiveness rate of the Anti-Death Of Kexing and BNT162b2 was 98.3% and 98.1%, respectively.
The study also showed that for people aged ≥ 60 years old, the effective rates of Kexing and BNT162b2 in preventing severe illness were 72.2% and 89.6%, respectively, and the effective rate of preventing deaths was 77.4% and 92.3%, respectively.
Covid-19 is still at a global high level. According to Worldometer real-time statistics, as of about 6:30 Beijing time on April 25, 2022, the cumulative number of confirmed covid-19 cases in the world 509457781, and the cumulative number of deaths 6242796. Globally, there are 412018 new confirmed cases and 1160 new deaths in a single day.
Vaccination is an important part of the pandemic response. According to our world in data, 65.1% of the world's population has been vaccinated with at least one dose of COVID-19 vaccine, and so far 11.52 billion doses have been given worldwide, with 11.03 million new doses per day.
Experts said that Hong Kong studies have shown that the completion of 3 doses of inactivated vaccination is a necessary means to deal with the epidemic in Omikerong, especially for the elderly aged 60 or over 80 years old, the third dose can significantly reduce the case fatality rate, reduce the medical run, and carry out the third dose of vaccination in the juvenile population can also significantly reduce the risk of transmission and the burden of disease.
The study by the Ministry of Health of Chile also argues that the use of a three-dose regimen as a base immunization for inactivated vaccines should be considered.
A study published in The Lancet on 22 April also showed that enhanced vaccination of BNT162b2 significantly improved protection against Omikeron, with an effectiveness of 85% and 77% for hospital admission or emergency treatment within 3 months, but dropped to 55% and 53% respectively after 3 months. The study analyzed electronic health records of members of the Large Integrated Health System (KPSC) in California, U.S.A., between December 1, 2021 and February 6, 2022, including 11,123 hospital or emergency admissions.
Some experts said that from this study, it can also be seen that all current vaccines may face the risk of delaying the decline in effectiveness over time, including the impact on severe illness and death protection still needs further study, but the fact that three injections have become the current default basic immunity is an indisputable fact.